
import { useIntersectionObserver } from '@vueuse/core'
// 定义懒加载
export const lazyPlugin = {
    install(app) {
        app.directive('img-lazy', {
            mounted(el, binding) {
                //el:指令绑定的元素 img
                //binding: binding.value 指令等于后面绑定的表达式的值：这里指图片url
                // console.log(el, binding.value);
                const { stop } = useIntersectionObserver(
                    el,
                    ([{ isIntersecting }]) => {
                        // console.log(isIntersecting)
                        if (isIntersecting) {
                            //进入视口
                            el.src = binding.value
                            stop()
                        }
                    },
                )

            }

        })
    }
}